1. Field of the Invention
The present invention relates to a wireless communication apparatus and a wireless communication method. For example, the invention relates to a method for switching a communication channel in detecting an interference signal.
2. Description of the Related Art
Conventionally, in a wireless LAN system in accordance with the IEEE (Institute of Electrical and Electronics Engineers) 802.11a standard, wireless communication is conducted using a 20-MHz frequency band.
In accordance with Radio Law, when radar is detected in the in-use communication channel, the communication in the communication channel is prohibited for a given period. The related method used is disclosed in Jpn. Pat. Appln. KOKAI Publication No. 2007-005897, for example. Radar here means radar as used by the Meteorological Agency, for example.
Therefore, in the IEEE 802.11h standard, a procedure in which the wireless LAN base station switches the communication channel to another usable communication channel is defined when radar is detected.
In switching the communication channel, the wireless LAN station transmits a channel switching notification frame to all the wireless LAN terminals in order to notify the wireless LAN terminal of a communication channel of a transition destination. Adoption of the above method enables long-time prohibition of wireless communication to be avoided upon detection of radar.
However, in the IEEE 802.11h standard, information of only one communication channel of the transition destination can be set at the channel switching notification frame. Therefore, in the case where radar exists in the communication channel of the transition destination, unfortunately, the communication cannot be conducted in the communication channel of the transition destination.